?WinForms控件開發(fā)：自定義數(shù)據(jù)網(wǎng)格與ORM集成

using System; using System.windows.Forms;  public class CustomDataGridView : DataGridView {     public CustomDataGridView()     {         // 初始化自定義數(shù)據(jù)網(wǎng)格         this.DoubleBuffered = true;         this.EnableHeadersVisualStyles = false;         this.ColumnHeadersDefaultCellStyle.BackColor = System.Drawing.Color.LightGray;     }      // 自定義列的示例     public void AddCustomColumn(string headerText, Type columnType)     {         DataGridViewColumn column = new DataGridViewColumn();         column.HeaderText = headerText;         column.CellTemplate = (DataGridViewCell)Activator.CreateInstance(columnType);         this.Columns.Add(column);     } }

using System; using System.Windows.Forms; using System.Linq; using Microsoft.EntityFrameworkCore;  public class MyDbContext : DbContext {     public DbSet<person> People { get; set; }      protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)     {         optionsBuilder.Usesqlserver("YourConnectionString");     } }  public class Person {     public int Id { get; set; }     public string Name { get; set; }     public int Age { get; set; } }  public class MainForm : Form {     private CustomDataGridView dataGridView;      public MainForm()     {         dataGridView = new CustomDataGridView();         dataGridView.Dock = DockStyle.Fill;         this.Controls.Add(dataGridView);          LoadData();     }      private void LoadData()     {         using (var context = new MyDbContext())         {             var people = context.People.ToList();             dataGridView.DataSource = people;         }     } }</person>

public class CustomDataGridView : DataGridView {     // ... 之前的代碼 ...      public void ApplyCustomSort(Func<person object> sortFunc, bool ascending)     {         if (this.DataSource is List<person> people)         {             var sortedPeople = ascending                  ? people.OrderBy(sortFunc).ToList()                  : people.OrderByDescending(sortFunc).ToList();             this.DataSource = sortedPeople;         }     }      public void ApplyCustomFilter(Func<person bool> filterFunc)     {         if (this.DataSource is List<person> people)         {             var filteredPeople = people.Where(filterFunc).ToList();             this.DataSource = filteredPeople;         }     } }</person></person></person></person>

public class CustomDataGridView : DataGridView {     // ... 之前的代碼 ...      public void EnableVirtualMode(int totalRowCount)     {         this.VirtualMode = true;         this.RowCount = totalRowCount;          this.CellValueNeeded += (sender, e) =>         {             // 實現(xiàn)虛擬模式的邏輯             if (e.RowIndex >= 0 && e.ColumnIndex >= 0)             {                 // 這里可以從數(shù)據(jù)源中獲取數(shù)據(jù)                 e.Value = "Sample Data";             }         };     } }

public class MyDbContext : DbContext {     // ... 之前的代碼 ...      protected override void OnModelCreating(ModelBuilder modelBuilder)     {         modelBuilder.Entity<person>()             .HasMany(p =&gt; p.Orders)             .WithOne(o =&gt; o.Person)             .HasForeignKey(o =&gt; o.PersonId)             .OnDelete(DeleteBehavior.Restrict);     } }</person>